BE® Imaging

Bandwidth Extension (BE®) has historically been run post-migration and it works very well, but is dependent on the imaging with conventional frequencies.

Running BE® before migration provides an increase in spatial resolution. The improvements come from three sources. First, the increase in the bandwidth pre-migration will reduce both vertical and lateral wavelets post-migration and increase both vertical and lateral resolution. Second, the sharpness of the gathers before migration allow for a much more accurate initial velocity model. This in turn allows for a more accurate stacking velocity model, which translates into a more accurate interval velocity model. Third, after migration, since the common image gathers are higher resolution, this will allow for a more accurate picking of depth errors and horizons to go into our tomographic updating software.

Needless to say, high resolution seismic coupled with high resolution velocity demands a high resolution set of migration parameters, so things like bin spacing, offset spacing, depth sample and spatial velocity sampling for updating need to be revisited after BE®. The resulting image will provide a better representation of the subsurface structure and stratigraphy.

Flow:

• BE® run on final un-migrated gathers
• Hi-res migration velocity model building
• PSTM or PSDM with High Resolution data and velocities as input
• Gather Conditioning
• Stack

Benefits:

• Improved spatial (lateral and vertical) resolution
• Sharper, crisper faults
• Better imaging of thin stratigraphic reservoirs
• Best possible input to pre- or post-stack inversion, OVT, Pore Pressure Prediction

BE® Imaging Input Data Requirements

Minimum Processing:

• Geometry Application and Corrections
• Spherical Divergence
• Shot Domain Noise Attenuation (if necessary)
• Deconvolution
• Refraction Statics and Residual Statics
• No NMO correction applied
• Data should be at the same datum as the velocities
• Any final datum correction should be in the headers for application at a later time

Required Header Information:

• Source Line and Source Station
• Source X and Y
• Receiver Line and Receiver Station
• Receiver X and Y
• CMP-X and CMP-Y
• Inline and Crossline
• Unique Ensemble Identifier (Field File Number or CDP Number)
• Final Datum Correction Value